Byte to Tebibyte

A byte contains exactly 8 bits. This is the universal modern standard, though early computing used variable byte sizes (5, 6, or 7 bits). The 8-bit byte became universal with the IBM System/360 in 1964. Eight bits allow 256 possible values (0–255), sufficient to encode all ASCII characters with room for control codes.

Eight bits became standard because it is the smallest power of two that can encode all 128 ASCII characters (7 bits) with a spare bit for parity checking or extended character sets. It also maps cleanly to two hexadecimal digits (0x00–0xFF), making it convenient for low-level programming and hardware design. Earlier systems used 6-bit or 7-bit bytes; 8-bit won due to IBM's dominance in the 1960s–70s.

A nibble (also spelled nybble) is 4 bits — half a byte. A nibble represents exactly one hexadecimal digit (0–F). The term is used in low-level programming, embedded systems, and BCD (binary-coded decimal) encoding. It is not an SI unit and rarely appears in general computing contexts outside of hardware and systems programming.

It depends on the character and encoding. In UTF-8 (the dominant web encoding): ASCII characters (A–Z, 0–9) use 1 byte; common European accented characters use 2 bytes; most Asian scripts (Chinese, Japanese, Korean) use 3 bytes; emoji and rare characters use 4 bytes. A plain English text file is efficiently encoded as 1 byte per character in UTF-8.

In most modern usage, byte and octet are synonymous — both mean 8 bits. "Octet" is preferred in networking standards (RFC documents, ITU specifications) to avoid ambiguity from early computing where byte sizes varied. Internet protocol headers are specified in octets; operating systems and storage devices use bytes. In practice you will encounter "octet" mainly in formal networking documentation.

TB (terabyte) = 10¹² bytes = 1,000,000,000,000 bytes (SI decimal). TiB (tebibyte) = 2⁴⁰ bytes = 1,099,511,627,776 bytes (IEC binary). TiB is 9.95% larger. The practical consequence: a 1 TB hard drive (decimal) holds 0.9095 TiB. This 10% gap is the primary reason drive capacity appears lower in the OS than on the box.

ZFS and Btrfs are copy-on-write filesystems designed for TiB-scale pools with built-in features that traditional filesystems lack. ZFS supports inline deduplication — a 10 TiB pool with 40% duplicate data might show 6 TiB of logical usage but only consume 3.6 TiB physically. Btrfs offers transparent compression (zstd), where a 4 TiB dataset of compressible log files might occupy only 1–2 TiB on disk. Both support snapshots that initially consume zero extra space, growing only as data diverges. These features make "used space in TiB" surprisingly complex to report accurately.

Yes. Linux tools (df -h, lsblk) display storage in IEC binary units: KiB, MiB, GiB, TiB. df -h output showing "1.8T" for a 2 TB drive is reporting 1.8 TiB. Modern Linux distributions correctly label these as TiB in technical contexts. This is one of the areas where Linux is more technically precise than Windows or consumer storage labels.

RAID arrays lose capacity to redundancy: RAID 1 mirrors two drives (50% efficiency); RAID 5 loses one drive worth of capacity; RAID 6 loses two drives. A 4-drive RAID 5 array of 2 TB drives has 3 × 2 TB = 6 TB raw usable (decimal), ≈ 5.46 TiB, minus filesystem overhead. Enterprise storage also reserves space for spares, snapshots, and wear levelling, further reducing usable TiB.

No. A tebibyte (TiB) = 2⁴⁰ bytes = 1,099,511,627,776 bytes — about 1.1 trillion bytes. Exactly one trillion bytes = 10¹² bytes = 1 terabyte (TB, decimal). The tebibyte is approximately 10% larger than a trillion bytes. "Terabyte" is often casually used to mean "1 trillion bytes"; "tebibyte" is the precise binary equivalent at 1,024 gibibytes.